As shown in FIG. 1, a prior art electric fan head 10 is provided with a swing shaft 20 which is fastened thereto for fastening the fan head 10 with a leg connection seat 30. The swing shaft 20 serves as a swing axis. The fan bead 10 is provided at another end thereof with a rotary plate 40 driven by a deceleration device 50 which is actuated by a motor 60. The rotary plate 40 is provided at one side thereof with an eccentric shaft 41 which is fastened with a connection rod 70. The swing shaft 20 is provided with a locating rod 31 having a connection hole 310 engageable with a fastening screw 710 for fastening the locating rod 31 with a fitting hole 71 of the connection rod 70. Now referring to FIG. 2, the electric fan head 10 is caused to swing back and forth in a sectoral manner by the rotary plate 40 when the motor 60 is at work.
As illustrated in FIG. 3, the locating rod 31 of the leg connection seat 30 is fastened with the connection rod 70 by the fastening screw 710 which is received in the fitting hole 71 of the connection rod 70 and the connection hole 310 of the locating rod 31. The work of fastening the locating rod 31 with the connection rod 70 by means of the fastening screw 710 is rather time-consuming. In addition, the fastening screw 710 is vulnerable to becoming loosened by the swinging connection rod 70, thereby causing the electric fan head 10 to become incapable of swinging when the electric fan is in motion.